High serum potassium; associated with cardiac arrhythmias

Aetiology

Conditions

• Acute kidney injury
• Chronic kidney disease
• Rhabdomyolysis
• Adrenal insufficiency
• Tumour lysis syndrome

Medications

• Aldosterone antagonists (spironolactone and eplerenone)
• ACE inhibitors
• Angiotensin II receptor blockers
• NSAIDs
• Potassium supplements

Clinical features

• When present, the symptoms of hyperkalemia are nonspecific and predominantly related to muscular or cardiac function - fatigue, muscle weakness, palpatations/chest pain

Investigations

• Bloods: U+Es (potassium, creatinine, urea, eGFR)
• ECG:
  • Tall peaked T waves
  • Flattening or absence of P waves
  • Broad QRS complexes